Spider Move: Muscles-Hydraulic Pressure

Spiders are second only to snakes in the dread departemnt, but they&#39;re actually very helpful arachnids who are only deadly to humans under the worst case scenario. Of the more than 40,000 species, very few spiders are even venomous to humans. Learn everything you ever needed to know about these 8-legged wonders in today&#39;s episode. http://goo.gl/5bv3ls